GOP primary voters in South Carolina and caucus goers in Iowa, two states that play influential roles in the presidential primary process, are open to an earned path to citizenship for undocumented immigrants, according to four focus groups conducted in March by the center-right organization Resurgent Republic.

Forty people who voted in primaries or caucuses in each of the last two elections and described themselves as conservatives participated in the focus groups. Immigration has long been seen as a toxic subject for these voters. The focus group results are unscientific, but organizers hope they represent a sea change for the immigration issue in the GOP.

Primary voters who took part in the focus groups articulated support for a path to citizenship, as long as it meets certain criteria, such as passing a criminal background check, paying fines and back taxes, learning English and civics, and going to the so-called "back of the line" of immigrants seeking permanent residency. Any immigration bill must include increased border-security measures, the voters said. Those provisions match language in a bipartisan immigration bill being crafted in the Senate and a plan supported by President Barack Obama.

When asked which they would support, a mass deportation plan or comprehensive immigration reform that includes a path to citizenship, 19 in 20 focus group participants in South Carolina chose the latter.

"It was far more positive than I thought," Republican pollster John McLaughlin, who administered the focus groups, told a group of reporters at Resurgent Republic's Alexandria, Virginia, headquarters on Wednesday. "To me, to have Republican primary voters this positive, it represents a real change from the past few years where they are almost welcoming the idea that we can get more Hispanic voters to vote for us."

Ed Gillespie, the former Republican National Committee chairman and director of Resurgent Republic, recalled getting "lit up for 40 minutes" on conservative talk-radio in Iowa when he defended President George W. Bush's support for immigration reform in 2007.

"To see these results out of Iowa with caucus goers was of great interest to me," he said. "I think the dynamic is changing."

Those findings might be encouraging for Republicans who back immigration reform and are thinking about running for president in 2016, such as Florida Sen. Marco Rubio, or who face reelection in 2014, like South Carolina Sen. Lindsey Graham.

But the focus-group report comes with some weighty caveats to consider.

Immigration does not rank high on the list of priorities of the GOP primary voters who participated in the focus group. And they were familiar with very few policy details that pertain to immigration. McLaughlin said that most focus-group voters did not even recognize the term "path to citizenship" and were only able to form their opinions after being presented with descriptions.

That may explain why GOP politicians like Sen. Rand Paul (Ky.) have been reluctant to use the phrase. But it might also represent a potential obstacle for Republican supporters of the bill.

Focus-group participants did not believe a path to citizenship was tantamount to amnesty after it was presented as a tough, lengthy process. But impressionable primary voters could be swayed by opponents who insist on calling it amnesty and describe it as a reward for entering the U.S. illegally.

"One of the key things for Republicans is to get the idea out that there are all these conditions in here and it's not amnesty," McLaughlin said.

That might not be an easy thing to explain.

"It may be that sometimes you have to beat the bumper sticker with the one-pager," Gillespie said. "We and others are trying to see if there is language that captures all this more readily."

McLaughlin also said that GOP primary voters he spoke to harbor a "deep middle-class resentment" at the notion that President Obama attempted to "buy the Hispanic vote" by touting immigration reform and his healthcare law. It will be crucial for Republicans to explain that undocumented immigrants who become legalized will not be eligible for federal benefits until they earn citizenship, McLaughlin said.

"This is just their talk, it doesn't mean it's true, but [a man in South Carolina said], 'I heard they ran ads in Mexico for people to come to the United States to take food stamps,'" McLaughlin said. "It's that kind of mythology that you hear."

At the end of the day, these findings suggest that Republican voters may simply see immigration reform as a bitter bill they have to swallow in order to broaden their appeal to Latino voters.

"The instinctive resistance to immigration reform amongst Republican primary voters seems like it may be giving way to an instinctive resignedness to do it," Gillespie said.